NOTE: The mpi compilers are cross-compilers. The executable is built for the Blue Gene compute nodes, and will not run on the login nodes. We recommend using the mpi-wrappers for whatever compiler you're using. You will find the list of predefined mpi-wrappers for GNU and XL compilers in the Overview of How to Compile and Link page. If you try to use gcc or cc directly, you will generate code for the login nodes.